1. Field of the Invention:
This invention relates, in general, to protheses which are externally attachable to severed or amputated limbs and, more specifically, to an external prosthesis attachable to a severed or amputated limb which employs a magnetic field to help provide a secure, non-slip fit.
2. Description of the Prior Art:
It is common to attach a prosthesis or artificial limb externally onto the stump of a limb of an individual which has been amputated or otherwise severed in order to provide a measure of use of the limb to the individual. In general, prior art external prostheses employ a concave socket formed at the attachment end to receive the residual limb. The socket is generally configured to accommodate the residual limb, and generally contains some type of padding material to help cushion the end of the residual limb. The strap and harness assembly is utilized to attach the external prothesis to the stump of the limb. During use of the weight bearing limb, such as a leg or arm, forces are generated which are transmitted through the prothesis directly through the flesh surrounding the stump. Since it is difficult to insure a secure, non-slip engagement between the prothesis and the limb, the forces generated during use of the prosthesis create movement of the prosthesis relative to the stump which results in irritation of the flesh surrounding the stump and discomfort to the wearer. This makes it difficult, if not impossible to effectively use the prosthesis in a normal manner.
Various solutions to the above-listed problems have been proposed. Some, such as U.S. Pat. No. 2,578,019, concern themselves with the external prosthesis itself. Others, such as my U.S. Pat. No. 4,547,912, proposes using an internal prothesis attachable to the external prothesis. My patent proposes employing an amputation apparatus comprising two parts. The first part is a cap having an internal cavity for insertion over the bone and an opposed outwardly extending boss. The second part comprises a plate having an internal cavity mountable over the outwardly extending boss of the cap. The plate has a radial extent substantially greater than the radial extent of the cap to define equally weight distribution surface for internal and external forces over the entire bottom surface of the stump.
My co-pending U.S. Patent Application Ser. No. 011,160, filed Feb. 5, 1987, a disclosure of which is herein incorporated by reference, proposes various refinements and improvements to the two-part internal prosthesis. It proposes using a bone end pressure distributing means disposed completely within the residual limb and an open bottomed bone end containing means attached to the bone end pressure distributing means. The embodiments disclosed in the above-referenced application may be used with conventional external prosthesis, such as that disclosed in U.S. Pat. No. 2,578,019. Alternatively, by employing a bone pressure distributing means comprised of a magnetically attractive/transmissive material, the new and improved internal prothesis disclosed in my co-pending application may be employed in conjunction with the device of the present invention.
None of the prior art external prostheses with which the inventor is acquainted have any provisions therein for inducing a massaging effort in the stump of the residual limb. One of the primary problems with amputees is poor circulation to the stump because the circulatory system has been disrupted. This problem is exacerbated by the convention external prostheses which even further inhibit the already poor circulation in the stump.
Thus, it would be desirable to provide an external prosthesis for use with an internal prosthesis attachable internally to a severed or amputated limb, said internal prothesis being comprised of a magnetically attractive/transmissive material. It would also be desirable to provide an external prosthesis which, when used in conjunction with the internal prosthesis disclosed in U.S. patent application Ser. No. 011,160, filed Feb. 5, 1987, would provide a more secure, non-slip fit, and enable the user to function in a comfortable and adaptive manner. It would also be desirable to provide an external prosthesis which is capable of massaging the residual limb to improve the internal circulation thereof.